1. Field of the Invention
The present invention relates to a process for the purification of waste water, wherein the waste water is fed into a cycle of a filtration stage, the cycle taking the retained matter of the filtration stage back to its inlet point whereby a concentrate is set up in the filtration cycle, and wherein concentrate is taken out of the filtration cycle and is further introduced into a treatment stage for physical and/or chemical treatment; and it also relates to an apparatus that is suitable for carrying out this process.
2. Description of the Related Art
In a known process of this kind (EP 0 503 649 A1), the concentrate after having been subjected to the physical and/or chemical treatment is introduced into a biological reactor upstream of the filtration stage, which also receives the incoming waste water for the purpose of biological treatment. Already from this known process very good treatment results can be expected.